Electrolytic phonograph pickup



Aug. 29, 1950 J. J. ROOT 2,520,812

ELECTROLYTIC PHONOGRAPH PICKUP Filed Jan. 15, 1946 El. E J

a ial [HQ 39 27 {El [1g] Patented Aug. 29, 1950 UNITED "STATES PATENT OF F-ICE 2,520,812 ELECTROLYTIC PHONOGBPl-I PIQKJJP John J. Boot, New-Yorkr Nl- Y. .ApplicationJanuary 15, 1946, Serial-.1 \f0.;6 1 1 ;28

This invention relates totl 1e productiomof electrical- 'voltages; in response lto sound fre- 'q y a tuation. tQ- -S. p rt cula i-d refi to 7 electrical pick up-units suchas maybe used. with conventional phonograph "recordsor to microphoneswhichgenerate electricalimpulses pursuant: :to sound waves impinging. pn'their diaphragms.

Referring particularly to phonograph- ,pick up units; a widely used device ;is -the well'knowng.

Rochelle salts crystals which vibrate-mechanically when actuated ,by soundwayes and generate a' corresponding alternating voltage by ;-.;pie zo- :felectric action. Anothertype of pick-upunit is v C the "so-called dynamic or magnetic-unit. This,.,' type relies upon, the production of a- -mag n etic field and the cutting thereof; by a movable armature so 'as;to produce alternating voltages through electromagnetic induction.

"The aboveementioned self-generating units each have disadvantages;in theiroperation.yyEor ampl th rystal typ evelo s ra h low voltages and is fragile. The; magnetic: -ty pe is heavy and usually requires counter balancing-by an oppositely directed force so as notfiapress down too heavily on therecord. In both systems harmonics may be produced and ;damping oiithe voltage generating;-2 movements; often;r equired T1130 overcome such, defects.

. Bearing, the foregoing-in mind,;i t1 is;an object of the presentinverrtion to produce aself-gencrating type of pick-,upunitwhich-shallproduce considerably higher voltages than do conven- -.p:tional pick-up devices.

' Another object of this invention is to produce a pick-sup unitjof. extreme lightness so as not to bear down excessively -on avphono'graph-record,

. for example.

such a device which shallgbe; constructed: seas; to be suitable for both? simple; orpush-pull; inputs 'Another object of this invention is to produce a light-weight pick-up unit'whichashal-l have-high,

sensitivity, low noise level; high fidelity and shall be 'sufiiciently sturdy-to resist damage through ordinary handling thereof.

Another object of my-invention is to produce to an audio amplifier and which may-be adapted "I' to either lower-high impedancev a rupliiiiers.

x. Other objects oi'my invention willbe -apparent -fro1nthe, following de seription-, i-tbeingunder-.1

stood that the above-general statements of the objects of my invention are intended-to-describe I and not limit itin any, manner.

t In the drawings,

- Fig.1 is atop plan view of a"piclg upllunitcon-v structedj according to the present invention the top thereof being jt'ion ofits parts.

l'il

removed to illustrate theposi- ,Eig. Zis a cross-sectional view taken downwardly through the central'portion of the unit.

,,Fig 3 is a somewhat diagrammatic vievv illustrating ,the electrical action ofthe electrodes ihinwe unitpolystyrene and various 7 'acrylate and vinyl resins.---However, any equivalent material, such as rubber, or metal if desired, may be utilized.

The bodyl0 of-the unit is a chamber having relatively thick walls I l and a thin floorv l2 which is preferably, but not necessarily, provided with a corrugation l3v Disposed centrally of the floor 7 l2 and integral therewith is the 'needle holder [4 in which a setnscrew l5 retains a phonograph needle .16. The needle holder 14 by itsiintegr'al formation with the .thinfioor l'l is flexiblyconnected .to the body ,Hl. so as .to becapableof pivotal movement relative thereto with theaxis.

at the pivotpoint I1. =While the needle holder :14 is rigidcompared to the floor [2, it is sufficiently narrow to.,permit pivotal actuation thereof as hereinafterdescribed It will beobserved that the needle holder 14 extends; into the; chamber forrnedby the body) of theunit. Secured to the internally. disposed end of needle holder v I4 is an. electrode member ltl i which partakes of the pivotal movement of the holder, Thus, referring. to Fig. 2,.theelectrode -mernber-;- I8 is illustrated as beingtilted in a vertical? plane, 1 by time of. lateral l actuationfof needle 15;; Electrode member 18 is duali'n nature 1 and may bet formed-ot two dissimilar metals designed t a' t as o t v diu at a P in electrodes when immersed. in a suitable .elecq trolyte Many metals exhibit this .iunction g For --,example, leadperoxide and sponge. lead. will form positive and negative electrodes respectively when[immersedv in a solution-of sulphuric acid and water. Similarly, nickel: peroxide andj fiiiely divided. iron wil 1. form. the positive. and; negat ve electrodes respectively .in i'an alkaline" type of electrolyte. In thepresent.embodimentasrnple combinatiorl of. zir ic.and,copperplates is ut lized. Such combination produces 'a l negative jterjmir'ial sense The electrode members Wini b formedby welding Very thin zinc and copper plates together to produce a laminated construction, it is also practical to electrodeposit 'a zinc plate'on a th-i'n copper member or reverse the procedure; in that a zinc member may be' copper-plated. The electrodeposited plate. should beof the same thickes's" as'Tth' me berupfo'n which-"it is deposited.

will beinidersmod that the usenofi zinc and copperncombinations iseoptional iidltha other materials; such'i astfgrepmte; silver and ilarious iger samen ss be'employed. 1 r

44 fieierring to i l the electrode .meniber. l8 is connected by insulating post le to ,another'e'lejctrpde member .20: constructed'aSQeIectiQHe l8 but havings its plates;reversed relative' thereto. yInother words; thewzinc plate is uppermost, whereas in the central electrode- 18 'the copper plate is uppermost. Central electrode la is lik v ise;connected =to electrode 2i by rig insulating post 22. Electrode members 20 and 2 l -are sup- ,-.-por,ted by a-side wall of'body JG by pivot -members 23.and ;241which,; likethe postsi lfl and;22,

5.1 may kbe. .of: plastic j material and V formed zw ith sitpointed end s a ltoxdec e se f c o wii a 1-; type .of hearing means; provided in said side-avail. riSaid bearing: meansrmay take ;the :formjpf an -ordinary depression; 1 It will be apparent that I ac'tuation of therneedle l6, as illustrated inFig. 2- !Will pivot" the electrode members I 8 ,1 ilk-and 2 l odilyiwithin'the'pick-up unit: 1

s "-.Di'sposedi-laterally'of the pivoted emanate the e'nd electrodetmembers 25; 26 andzZkon-One side 'thereof, andzith'e electrode memberst23n29 and 30 on-the other side thereof The laterally dislposr electrode members" are stationary and avef'th e same sequence of plate disposition Ias asf'tlie turnables'ectionf Thusffithe' center 4 her 29, while member 26 is connected by wire 40 to member 21.

Referring to Fig. 2, in the absence of actuation of the needle l6, member i8 is disposed in the 5 same plane as members 26 and 29. The body it! is filled with an electrolytic solution, as stated above; Accordingly, interactions between opposite electrode plates will be produced, tending to. generateelectrical voltages. However, any in- 10 teractionbetween the zinc plate of member 26 and the copper plate of member i8 is neutralized 1 or cancelled by the action of the copper plate of member 26 with the zinc plate of member l8. Accordingly, there will be no difference of postentialpbetween electrode members 26 and [8. The same condition will prevail with respect to .i anypotential difference between member I8 and member 29. However, lateral actuation of the needle l6 in response to the Waves in the grooves of a phonograph record will at any one time produce a con'dition' such as illustrated in the dotted-linesfof Fig". .22 Itl willlbe' noted therein "that {the zi'nc'side of electrode member l8 i's pre- "'sent'ed so as to have a greater co-acting surface -wan+me copperside of. member 25. 'Conversely, the copper side of member I8 is withdrawn with respect to co-action with the zin'c 'side of member 26. Accordingly, a positive voltage willbe developed at electrode member 26; While a nega- 30 tivejvoltage will be developed on the zinc'side of central electrode member !8. now' the"co-actionbetween electrode member l8 and member 29, it'will beobserved that the tiltingof member 58' presents itscopper side to inember29f'sd'as toefie'ct a co-action with'the zincside" of member 25. "Simultaneously, the '"fz'i'nc side orjmemb r" i8 is "withdrawn inrespect to ce-amen with the "copper side of member'29. Accordingly, a positive voltage" is developed at the copper side of: member iB, whi le a negative volta'geis developed at member 29. f -It will] be observed that the sequence of "the iouifvoltages developed is that of positive; negativfpositive, negativaso that if these voltages are connected in an electrically series'relatiom s 1p; thetdtal voltagewm bethe' sum :of "the '-voltages'p foduced Referring-to Fig .'-3g thetilting'of the central v section of electrode members is illustratedx'lt *will" be noted-that the proper positive; negative sequence is observed throughoutthe successive V "e1ectrodesfthejconnectionsof wires 39 'and fl carrying out 'this purpose; The 'voltagebetween terminal 37 and 38 will be'substantially the sum 5 of"'all the separate voltages developed. between "each electrode member? 'fIn' the? arrangement Considering "fmembe r' 3i wl'rich;fri ctionally engages electrode shoWnFthe"rowfiof .zcentral electrode .members 'j mernbers 25, 25 and '2 'i;;is formed; 'with afpost transverse to the pivoted section have theirccop- Iii which is retained, against la side wall; of the persides uppermosti inora'ler-to preservefsuch seii body IO, as by a set screw 33.; Channel" inber q encey'as willibe apparent by following the voltf3] v is of; insulating material scene's o ni=; of the 7 {thermoplastic latens. sj or which the bo y" It T is formed.) A similar method of supporti's pi'of 'ch'annel member 34ihaving the set renas-enga ingthe post 36. A metallic wire3'l serving as "jgone terminal a the unit i s'led through aside llof body ;l0'vvhere it maybe embddedand k) conducted through channel 3! toiele ctrode "Ifnember 25. Similarly, a metallic wire 38 is' e'm- 1 beddedin an opp site side wall: and is conducted electrode member 30 5c as to form anfoppote m na -.5. I o d rvit mai t in Proper e flltii ii ilh' weez .iheLSHQ l Y l lecir d ln bersir'nember '28'is connected bywire se'tdmemthe electrolytic solution functions as an electrical: connection. between the cells described: If a de.-' sired, anelectrolyte having a gelatin base may. In this event, the gelatin itself.

bers arranged for co -action as illustratedin Fig.

2.,a1'1dwhereinthe turnable element produces additive voltages.

.The relatively high resistance electrolyteprow duces avery slight de-activating efiectupon the electrode members, the effect beingso sli ht as to be entirely unnoticeable even after a considerable period of time. The instant device permits the use of such an electrolyte because practically no current is drawn therefrom, the pick-up merely serving'to produce voltages for applica-' tion' to the grid of a vacuum tube. Since a vacuum tube is a voltage actuated device, a further advantage of such construction is that the pick-up or'voltage generating device ha'sfan. extremely long life because no current is drawn In this respect, its life is" much" greater'than the so-called shelf-life of a bat tery because even after the usefulness of a con-' therefrom.

ventional battery is outlived it still produces volt ages if very minute currents are drawn therefrom.

Opposite voltages will be developed as the externally actuated needle vibrates at sound frequencies and re-orients the plane of the movable section comprising the center member of each group of three electrode members so that the proper-audio frequency voltages are supplied between the terminals 31 and 38.

-In the event the device of Fig. l is applied to a simple vacuum tube apparatus, terminal 31 may. be connectedto the ground side thereof, while terminal 38 may be applied to the grid of the.

input tube. The impedanceof the unit may be regulated by the character of the electrolyte and.

the spacing between the electrode members so that high and low impedances are easily realized. In the event that a push-pull input is being served, the central electrode l8 may be grounded, whereupon opposite or out-of-phase voltages will .be developed at terminals 31 and 38. Thus, the requirements for push-pull operation will be met.

As illustrated in Fig. 2, the co-acting sides of the respective electrode members are brought to a sharp edge in order to produce greater sensitivity to slight actuation of the pivoted section while the corrugations [3 in the thin floor I2 permit pivoting of the section in response to such actuation. I

While Fig. 1 shows a successive group of cells contributing to the total voltage through series operation, it will be understood that a single pair of cells, one of which is movable in the manner described, while the other remains stationary;

is operative for the purposes of this invention. A simple combination, such as three electrode members disposed in Fig. 2 but wherein the terminals emerge from electrode members 26 and 29, is likewise feasible, the combination representing two cells which are series operated toproduce additive voltages. I Inthe embodiment of Fig. 4, a section similar to that of Fig. 2 is shown, but with a modifieddisposition of the electrode plates. The center electrode 45 has 'itszinc plate uppermost and,

asiwill benoted in Fig. 5, the end electrodes .of

th 'turnable. section-have their copper plates up-.l permost. The. laterally disposed stationary, seca.

tions comprise separated plates such as the cop-. per-plate .46 and the zinc plate 41 which are maintainedin their spaced relationship by .a conduct-.

ing metal 48 and are suspended in an electrolyte which fills thehollow body 5|. conducting rod 52 emb-eddedin-v the wall of the device serves as one terminal and in th arrangement shown in Fig. 4 it will be connected to the member 48 which connects the zinc plate 45 to its associatedcopper plate. Similarly, a member 54 connects the oppositely disposedcopper plate 55 and Zinc plate 56, while the electrical lead rod 51 serves as th other terminal of the device,. InFig. 5, which illustrates the modification of Fig. 4 as adapted to a plurality of groups of three elec-, trode members, the terminals 49 and 50, corbeing connected to the member 54.

responding to terminals 52 and 5?, are connected to the respective ends of the circuit.

When the electrode member 45 is pivotally actuated b the movement of the phonograph needle 59, as indicated in the dotted lines of Fig. 4, the balanced relationship existing between the electrode plates will be disturbed and the copper plate of member 45 will present a considerable area for co-action with the zinc plate 41, while the'zinc side, 'ofinmber 45 will be correspondingly withdrawnfrom copper plate 46. Accordingly, a" negative voltage will be developed at zinc'plate 5B which overcomes the neutralizing' positive voltage which is ordinarily cre-' ated'bythe copper plate 46.

connecting member 52 will have a negative potential. On the opposite side of the unit, opposite conditions will prevail, a positive potential being developed at connecting member 54.

' As' notedin Fig. 5, conducting wires BIB-and 6| maintain the Series relationship of the various cell structures. It will be appreciated, of course, that the stationary electrode members are constructed as are the illustrated cell members 46 and 41, and 55 and 55, while the pivoted section has the cell members or plates in contacting relationship. r i

Inthe event of terminal 49 or 52 may be connected to the ground thereof, whileterminal 5!! or 51 may be introduced in any suitable manner to the gridofa vacuum tube. If push-pull operation is desired,

an insulated wire. may be connected to the electrode member 45. This electrode member 45 1 being the electrical center of the unit, may be connected to the ground side of the amplifier, whereupon wires 52 and 51 or 49 andifl, will produce mutual. out-oi-phase voltages for appli-v cation to a pair of grids-in the push-pull input.

As in .the previous embodiment, either the series of nine or more electrode members may be utilized, or a simpl combination of either two or three. A..combination of three would appear as illustrated in Fig. 4.

It will. be, appreciated that the liquid electro-i lyte produces an inherent damping effect and contributes to the tonal fidelity of the system. The pick-up is, furthermore,.light in weight and produces high voltages by the series action described. lfdesired, a de-polarizing agent ofa conventionaltype may be utilizedto eliminate the efiectsyof polarization of electrode surfacea;

Suchpolarization will be extremely small,.how-

v ever,. becausepractically no. current is supplied 75 by-the' devicein normal operation.

An electrically.

Thus, the metal a simple input to an amplifier,

I have shown a preferred embodiment or my invention, but it is" obvious that numerous changes. and omissions may be. made therefrom: without departing from its spirit. The oorrnga: tions I3 may be omitted if the floor is sufii'ciently flexible and in this event, it may be desirable toomit the pivot members 23 and 24 since the electrode members mayhave a lateral as well as apivotal movement.

I claim:

I. A voltage generating device of: the character described comprising a chamber,' a pair of elec'* trode members fabricated of dissimilar metallic materials which form positive and negativeelec= trodes respectively when immersed in an electrolyte, said electrode members being mounted in said chamber, an electrolyte withinsaid chamber anclin which said members. are disposed so that voltages tend to develop across said electrode members throughelectrol-ytic coaction, and Vibrating means disposed externally of said chamber and connected to one of said'ele'ctrodemembers so as to' vibrate said connected member and vary its electrolytic coaction with the other electrode memben 2. A voltage" generating device of the characterdescribed comprising a chamber, a pair of electrode members, fabricated of dissimilarmetallic materials which form positive and negative electrodes respectively when immersed in an electrolyte, said electrode members being mounted in said chamber, an electrolyte within said chamber andin which. said members are disposed so that voltages tend to develop across said elec trode members through electrolytic coaction', means to normally maintain said electrode nieir'is bers. in aplane wherein no voltages are developed between them, and movable. means originating externally of said chamber for varying the plane of one of said members, said variationbeing op erative to affect the electrolytic coaction. of said. members. so as to develop alternating. voltages accordingly.

c 3 A voltage generating device of the character described comprising a; chamber, at least threeelectrode members mounted within said chamber, an'electrolyte within said chamber in which said; members aredisposed, meansto develop opposite voltages between the center electrode: member and the electrode members on each side thereof. through electrolytic action of said.mem-- here, said center member being movable in. re-

sponse to: external. actuation, means to move said center: memberssaid movement being operative to develop alternating voltages. of opposite polarity inv the respective electrode members on each side of said center electrode member through. electrolyticactionr r 4. A- voltage generating. device according to. claim 3 whereinwsaid. three members are nor mally oriented in a balanced relationship wherein no voltages. are: generated between. them and means originating externally oi said chamber for re-orienti'ngsaid-central member, said reorientation being operative to eflect opposite coaction-90f said: centecm'ember with the other two-members respectively so as to produce: oppo s-itevoltages.thereon.. V 5A voltage g'enerating device of the character described comprising a chamber, threeelectrode:

members mounted withinsaidchamben. an elec.-: trolyte within said chamber in which. said, three: members are disposed each saidmemher' com-:- prising a pair oropposite electrode platsa the v opposite plates of the centenmemberof said. three members being arranged for respective coaction with one electrode plate of the electrode members on each side thereof, said co-action producing opposite voltages on each of said end electrode members in respect to said center electrode membenrand means adapted to vary the positionv of saidxcenter electrode member at audio frequency rate whereby" said co-acti'orr produces opposite alternating voltages betweensaid. electrode member and said. end members-re l sp'ectively.

6. A voltage generating deviceof the character described comprising a chamber, three electrode members mounted within said chamber, an electrolyte within said chamber inwhichthree members are disposed, each said member comprisingapair of opposite electrode plates, the opposite plates of the center member of said three members being arranged for respective co-action with one electrode plate of theelectrodemembers on each side thereof, said co-action producing opposite voltages on each of said end electrode members in respect to said center electrode member, all of said three members being normally in alignment so as to balance the cogaction of said center member with the other members whereby. no Voltages are produced through electrolytic action, and meansv disposed externally of said chamber and operatively connected to saidcenter electrode so as to disturb said alignment whereby the co-acting surfaces of the opposing electrode members are varied, saidv variations being operative to produce opposite reactions on bothsides of said center electrode member.

7. A voltage generating device ofthe character described comprising a chamber, three electrode members mounted within said chamber, an; electrolyte within said chamberin which said three members are disposed, each said member comprising a pair of opposite electrode plates, the oppositeplates of the: center member ofisaidthree' members being arranged for respective co-action with one electrode plate, of the electrode members on each side thereof, said .co-action producing opposite voltages-on each of said end electrode members in respect to said center electrode member, and means adapted to vary the position of said center electrode member atan audio fre: quency rate whereby said co-action produces:op-- posite alternating voltages between said electrode member and said end members respectively, said end electrode members having their electrode plates disposed similarly, and said center electrode member having its electrode plates disposed oppositely with respect to said end member plate disposition.

8. A voltage generating device of the character described comprising a chamber, at least three) electrode members mounted within said chamber, an electrolyte within said 'chamber' in which said members are disposed, means to develop opposite voltages between the center electrode member and'the electrode members on each side thereof. through electrolytic action of said members, said. center member being movable in. response to external actuation, means to move said center member, said movement being operative to develop alternating voltages of opposite polarity in the respective electrode membersv on each side thereof, said electrolyte being of. high resistance and being operative to connect said voltages in a series relationship.

9. A.voltage generating device for feeding audio frequencyyoltages toa fvoltage operated amplifier thereof, comprising a chamber, a'pai'r or dissimilar electrode members mountedtherein, an electrolyte: of 'high'resistance within "said chamber in which-saidmembers are disposed so thatfvoltages to develop across the electrode 7 members thr'dugh electrolytic action, a vibrating devic jext'ei nalfof said chamber and connected to o e of said electrode members,-and means to pivo id connected electrode member" through the action ofsaid'v'ibrating device so astovary sdi'dl'ectrolytic co-action and produce alternating voltages therefrom, said electrode members being connected to said voltage operated amplifier so as to feed the same with said alternating voltages.

10. A voltage generating device of the character described comprising a chamber, a plurality of electrode members arranged in an electrical series relationship in said chamber, an electrolyte within said chamber in which said members are disposed so that voltages tend to develop across adjacent electrode members through electrolytic action, said electrode members being arranged in groups of three, means to electrically connect each group so as to effect the series relationship, one member of each group being movable so as to produce varying voltages through electrolytic co-action with the other members of said group, and means to produce said movement in response to external excitation whereby variable voltages are produced pursuant to said excitation.

11. A voltage generating device according to claim 10 wherein the center member of each group of three is movable, the movement of said center member afiecting opposite co-actions respectively with each end member of its group, said co-action producing opposite voltages at each of said end members, the voltages produced by said end members being combined with the voltages produced by the remaining groups in a series relationship.

12. A voltage generating device according to claim 10 where-in each electrode member comprises a pair of dissimilar metallic members, adapted for electrolytic co-action with the metallic members of an adjacent electrode member in its group.

13. A voltage generating device of the character described comprising a chamber, a plurality of electrode members arranged in an electrical series relationship and in groups of three within said chamber, a fluid electrolyte within said chamber, each said electrode member being formed of two opposed dissimilar metallic materials, each electrode member of each group of three thereof being normally in alignment whereby no voltages are produced in end electrode members of each group of three through balanced co-action of said electrode members, the center electrode member of each group being movable to disturb said normal alignment, said disturbance being operative to produce opposite voltages upon the end members of said group through electrolytic action, and means responsive to external excitation to disturb said normal alignmentso as to develop said opposite voltages upon the end members of each said group, all the voltages developed in each group being electrically added to form an aggregate voltage at the electrical terminals of the device.

14L. A voltage generating device according to claim 13 wherein said means responsive to external excitation comprises a pivoted member operatively connected to the center electrode members of each group, and a phonograph needle secured to said pivoted member so as to pivot the same pursuant to sound grooves ina phonograph. recer una i trodeirfmbers of different groups.

16. A voltage generating device of the chart n eser bs f inp i sie l a} them-P n a electiolyt within said chamber; a plurality oil elec; trode members arranged in an electrical series relationship in said electrolyte, said electrode members being arranged in groups of three, said electrode members each comprising dissimilar metallic plates adapted to eflect electrolytic coaction with the plates of an adjacent electrode member, the end electrode member of each group of three having its dissimilar plates spaced in said electrolyte, electrical connecting means for said spaced plates, the center electrode member of each group being movable between said end electrode members, said movement serving to produce varying voltages upon said end members by varying the areas of co-action therewith, and means pursuant to external excitation for efiecting the movement of said center electrode members.

17. A voltage generating device of the character described comprising a chamber, an electrolyte within said chamber, a plurality of electrode members arranged in an electrical series relationship in said electrolyte, said electrode members being arranged in groups of three, an electrical conducting wire between the end of one group and the beginning of the next group, said electrolyte serving as an electrical conductor between adjacent electrode members of the same group, each of said electrode members .comprising dissimilar metallic plates adapted to effect electrolytic co-action with the plates of an adjacent electrode member through the action of said electrolyte, the center electrodes of each group of three being connected together so as to be movable in common, said connected center electrode members being swingable so as to vary the action of said center electrode members with the end electrode members of each group of three, said center electrode members being normally disposed in a plane which is symmetrical to the plane of said end electrode members so as to produce equal and opposite electrical voltages with each end electrode member, and means originating externally of said chamber for varying the plane of said movable electrode members whereby opposite but unequal voltages are produced in the center electrode members with the respective end electrode members of each group of three so as to produce resultant voltages between each end electrode member and a central electrode member, said series relationship of said groups of three being operative to add said resultant voltages to produce a total voltage between the first and last electrode members of said device.

18. A voltage generating device of the character described comprising a chamber, a pair of electrode members fabricated of dissimilar metallic materials which form positive and negative electrodes respectively when immersed in an electrolyte, said electrode members being mounted in said chamber, an electrolyte within said chamber and in which said members are disposed so that voltages tend to develop across said electrode members through electrolytic co-action,

afid means brigin'ating" externally or said ehain- UNITED smmspgmwps her and connected torpne ofrsaid members for in' b f 1 N 'mg V Date r moving Said one member w Wvary the 116,553 "hick Dec, 27,1870 tent' of co action of"'said members and thereby 25 135 'YKookogey Ap 11 very the developed vql tages accordingly. 5 7 3734 5 :Hauvsey July 1 0 V e V, V .pr kPv ",-:-e-.. p 14;

v 1 REFERENCES -2-,357,02 6 Scherbatskoy Aug 29, 1944 {line iollqwing references veue'of record ip the 2,403,696 7 Warner July 9, 1946 eq .n r 254 3671 Bus Nov. .19 7 

